In previously known air-controlled settling apparatus of the kind to which the invention relates the air inlet and outlet valves of the air chambers associated with the individual settling compartments are arranged below the air vessel, and the air flows out of the air vessel through the air inlet valves into the air chambers of the settling compartments whilst being subjected to multiple deflection. The exhaust air duct is located a certain distance below the air vessel so that the air flowing out of the air chambers of the settling compartments through the air outlet valves also flows into the exhaust air duct and is subjected to marked deflection.
These known constructions are hampered by some considerable shortcomings. The free, unprotected arrangement of the numerous valves leads in operation to a considerable nuisance from noise which is also contributed to by the strong multiple deflection of the air streams caused by the valve arrangement (which also results in an undesirable pressure loss). A further disadvantage is the considerable expense caused by the large number of complete valve units which are required. The exhaust air duct provided in the interior of the valve arrangement also contributes to the expenditure on apparatus.
The object of the invention, therefore, is to avoid these shortcomings and provide an air-controlled settling apparatus wherein the construction cost is considerably lower and the noise of the settling apparatus in operation is markedly reduced.